Fragmentation bomb



Jan. ll, 1949. N. L. ETTEN I 2,453,576

FRAGMENTATION BOMB Filed Oct. 4, 1943 2 Sheets-Sheet- 1 Illl llll Ill' III Illl Illl Il" 2 Sheets-Sheet 2 Filed Oct. 4, 1943 Patented Jan. 1l, 1949 2,458,576 FRAGMENTATIN BOMB Nicholas L. Etten, Waterloo, Iowa, assigner, by mesne assignments, to the 'United States of America as represented by the Secretary of War Application October d, 1943, Serial No. 504,915 2 Claims. (Cl. 102-2l This invention relates to an improvement in fragmentation bombs, of the character usually adapted to contain a high explosive and adapted to be dropped from an aircraft for explosion upon contact With the earth or bodies thereon.

Such bombs are intended to burst into a multiplicity of fragments upon bursting discharged in all directions by the force of the explosion with suicient velocity that each fragment thereof constitutes a missile having destructive capabilities.

It has been the practice heretofore to construct such bombs with a casing or body in tubular form and provided at opposite endswith a nose and tail piece formed as steel forgings. These parts are usually telescoped over opposite ends of the tubular casing and screw-threaded thereon. The body then is filled with the explosive charge.

Upon detonation, such a bomb often expands as much as 30%, as is well-known. And as a result, the threads are sheared oil, whereby the nose and tail piece will be separated from the casing before the entire body can burst into small fragments. Therefore, only partial fragmentation of the bomb results from the explosion thereof.

The object of this invention is to improve the structure of the bomb for causing complete fragmentation thereof upon explosion, as well as simultaneous bursting of all parts thereof.

A further objectl of the invention is to improve the construction of the bomb to enable it to be manufactured more rapidly, at less cost, and with less material than has been possible heretofore according to known methods and constructions. Furthermore, this bomb is made from standard structural forms of tube and wire or bars, that may be fabricated and forged as a unit, without the necessity for using separate forgings for the nose and tall.

These objects are accomplished preferably by ceiling a Wire or rod about a steel tube and then shaping one or both opposite ends of the composite structure to form the nose and tail piece on the casing of the bomb. It is preferable that the Wire be applied hot to shrink tightly on the tube, and also that the opposite ends be forged to the proper shape.

A preferred embodiment of the invention is set forth in the accompanying drawings, in which:

Fig. 1 is a side elevation of a fragmentation bomb embodying this invention;

Fig. 2 is a side elevation, with parts broken away and in section, of a casing tube showing the Wire coiled thereon;

Fig. 3 is a side elevation, partly in section, of forging mechanism for the bomb casing;

Fig. 4 is a vertical section through a portion o-f the casing tube and coiled wire;

Fig. 5 is a similar View showing an end ring thereon; and

Fig. 6 is a longitudinal sectional View through the bomb. v

The fragmentation bomb in which this invention is shown, is constructed with an elongated tubular body B in Figs. 1 and 6, having a n ose N at one end thereof and a tail piece T at the opposite end. The nose N is usually constructed of somewhat thickened wall at the upper end and tapering to the thickness of the casing to which it is integrally joined, the latter being of uniform thickness, but tapering slightly at the tail piece portion thereof.

In constructing the bomb, I utilize a section of seamless steel tubing i, of sufiicient size and length to form the bomb of the desired capacity. The tubing l is adapted to extend not only throughout the body or casing B of the bomb, but also through the portions thereof constituting the nose N and tail piece T, as shown in Fig` 6.

The tube I is wound from end to end thereof with a single layer of Wire or steel rod 2 suitably secured at opposite ends by welding 3 to the tube l, as shown in Fig. 4. The wire 2 should be applied to the tube l while the former is hot so that it will shrink when it cools and adhere tightly to the tube. The wire is preferably keystoned when made so the convolutions thereof will fit snugly in side-by-side relation when wrapped on the tube l.

If desired, a ring l may be applied to the nose end of the tube l, and welded thereto as at 5 (Fig. 5). The wire coil 2 would then abut against the ring i as shown in Figs. 2 and 5.

After thus covering the tube with the coiled wire or rod, one or both opposite ends of the fabricated structure may be shaped as desired in finishing the bomb casing. It is preferable that both ends be forged to form the nose and tail piece integral with the bomb casing.

In forging an end of the structure, I may utilize the method and apparatus set forth in my former application on Method of forging tubes, Serial No. 458,238, filed September 14, 1942, which is now abandoned, as shown in Fig. 3. The end of the composite structure l-Z to be deformed should first be heated to a high temperature (approximately white heat), and then subjected to longitudinal impact blows by a hammer action.

In the apparatus shown, the numeral l0 represents the frame of the hammer, with a supporting anvil IIthereon. A drive shaft I2 is mounted in the frame I0, and carries a crank disc I3 thereon. A wrist-pin I4 on the crank disc I3 supports a swivel I5. Side arms I6, I6' pivotally connect opposite sides of the swivel I with links II, I'I', which links are attached to ears I8, I8' on a hammer head I9. The arms I6 have an interposed spring to keep them separated.

A split die 20 is mounted loosely in the hammer head I9, as set forth more in detail in my above-'mentioned application, adapted to surround and shape the enclosed end of the structure I-2, in this instance, the nose. A tapered pin 2l is mounted in the head I9 in position to project into the die 20 to forge a hole in the nose N which is required for mounting the detonator cap therein.

The composite structure I-2 is supported upon the anvil II in a rotating anvil fixture 22, having a pulley 23 thereon to be rotated by a motor 24 through flexible gearing, such as a belt 25.

The spring hammer strikes a succession of free hammer blows as the head I9 is reciprocated by the side arms I6, I6', and links II, I'I operated by the rotating crank disc I3. This will force the split die 20 over the enclosed end portion of the spring 2 and tube I, deforming these in forging action to shape the nose end of the bomb casing, as set forth more in detail in my above-mentioned application.

The tail piece may be formed in like or other suitable manner, or formed separately and applied thereto if desired. However, it is preferable to forge both the nose N and the tail piece T drectly on the composite structure I-2, as described above.

In this way the bomb casing may be constructed very simply, quickly and inexpensively, and of less metal than usually required. Furthermore, the unitary integral structure of the bomb casing, nose and tail piece insure simultaneous and complete fragmentation of all parts of the body, with more destructive effect thereof- This is of particular importance in air bombing in order to secure good coverage of the area directly below the bomb, in those 'cases Where the bomb is exploded before it strikes ground. For such use the solid type of nose, which bursts into fewer and larger fragments is definitely inferior to the present com struction.

I claim:

1. A fragmentation bomb casing comprising a thin-Walled inner tube of malleable metal, said tube comprising an undeformed body portion and being diminished at the front end to a streamlined contour terminating in a point portion, a heavy malleable Wire coil of substantially quadrilateral cross-section coiled on said tube including the diminished portion thereof, said wire being of a material readily frangible on explosion, the inner surface of said coil completely covering and contacting substantially all points of the outer surface of said tube adjacent said coil, the outer surface of said coil being formed to a smooth unbroken surface conforming generally to thev streamlined contour of the inner tube, and the adjacent turns of said coil being in contact at substantially all points between the inner and the outer surfaces thereof to define lines of cleavage, the cross-section of the convolutions on said front end being of greater area than on the undeformed lbody portion.

2. A fragmentation bomb casing comprising a thin-walled inner Vtube of malleable metal, said tube comprising a body portion and being diminished at each end to a streamlined contour terminating in a nose and tail point, respectively, a heavy malleablel wire coil of substantially quadrilateral cross-section coiled on said tube from end to end, said wire being of a material readily frangible on explosion, the inner surface of said coil completely covering and contacting substantially all points of the outer surface of the said tube, the outer surface of said coil being formed to a smooth unbroken surface conforming generally to the streamlined contour4 of the inner tube and the adjacent turns of said coil being in contact at substantially all points between the inner and the outer surfaces thereof to define areas of cleavage, the cross-section of the coi1 convolutions on said n'ose point being of greater area than on the undiminished body portion.

NICHOLAS L. ETTEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain Oct. 15, 1915 

